But you are asking them not to use air con. Will they? Purposely buy 7 seater, you ask them to remove 2 seats?

take out side mirror and drive dangerously(they are there for a reason), change auto to manual(they bought auto for convenience, so looks like most of your suggestion won't work....

Right

Most of them doesn't work in real world.
1) Not to use air cond - Unless you are working and staying at Genting Highlands Resort where air cond are rarely needed, with our country's hot and humid climate esp. afternoon, air cond are still necessary. But, try not to set your air cond at maximum cooling level, instead adjust the air cond temp. according to the weather to reduce frequency of compressor kick-in and to preserve the lifespan of it's components (such as dryer, receiver, and compressor). And fan speed is set at 1 (low) or 2 (medium) depends on weather and cabin temperature.
2) Purposely buy 7 seater and remove 2 seats - For large families (>5 family members), a 7 seater mid-size MPV/SUV is usually used as their main family car rather than cramp in all together in a sedan/hatchback and cause hazard to others. So it's pointless for someone to buy 7 seater and remove 3rd row seats (like that buy Alza better as it's more towards 5+2, not fully 7 seater)
3) Take out side mirror - Totally unacceptable as it is required by law (the absence of either one or both side mirror can net you a ticket, this is true because even motorcyclist can get summoned by police due to absence of either one or both side mirror) and the usage of the side mirrors is to lookout for other vehicles at your side and also check for blindspot. But for some driver/riders, side mirrors are just an ornament as they like to change lane as they like (no need to look behind), including without signal or precisely signalling for 1 miliseconds then change lane straight away. Maybe when lorries/busses rammed their vehicle while switching lane, then they will realize the importance of side mirrors (esp. motorcyclists, only if they still alive).
4) Change auto to manual - Although FC for auto is a bit higher than their manual siblings (not applied to our 'Buatan Malaysia' cars), there must have a reason why people bought auto car. With all those slow moving vehicles and traffic jams especially at downtown areas, auto is more preferable as it gives more relaxed/smoother driving plus no need to cramp their left leg. Also some of their family members can't or no confidence driving manual cars, hence auto is easier choice for them even if he/she likes to drive manual especially if more than one family members share a car. However change auto to manual is only applicable if you drive Iswara/Wira 1.5 with archaic 3-speeder auto gearbox. IMO, whatever you will go for manual or auto car is the personal (or maybe family) choice.